In view of complementary features of both optical and wireless networks, the integrated optical-wireless (FiWi) (or WOBAN [4]) network has been proposed to provide a highbandwidth, low-cost hybrid access network as shown in Fig. 1.
The integration equips ONUs with the capability of modulating wirelessly received signals from wireless mesh routers to upstream optical signals transmitted to the RN and the capability of demodulating optical signals received from the RN and then wirelessly transmitting the signal to the WMN.
In other words, ONUs in FiWi network combine the function of traditional ONUs in PONs and gateways in WMNs together.
An alternative implementation of ONUs in FiWi network is to connect traditional ONUs in PONs with gateways in WMNs through wired links [5].